Process and apparatus for setting a flexible elongate body in a particular form

ABSTRACT

A process for setting a flexible elongate body, e.g. a wireshaped body, supported by a number of bearings in a particular flowing form in which the bearings are placed in such relative positions as to cause the body to assume a desired shape, and while the body and the bearings are being positioned relative to each other, they are rotated about their relative geometrical axes. Also an apparatus for carrying out this process is disclosed.

United States Patent Noordenbos Feb. 6, 1973 PROCESS AND APPARATUS FOR[56] References Cited SETTING A FLEXIBLE ELONGATE UNITED STATES PATENTSBODY IN A PARTICULAR FORM ,1 l l 1 l9 [76] Inventor: Pieter KlaasNoordenbos, Stokhorst- 078 5 2? 2 3x232 32, p e e Netherlands [22]Filed: Feb. 18, 1971 Primary Examiner-Frank T. Yost [211 pp No: 116,399Attorney-Stevens, Davis, Miller & Mosher [57] ABSTRACT [30] ForeignApplication Priority Data A process for setting a flexible elongatebody, e.g. 2 Feb. 20, 1970 Netherlands ..7002474 wire shaped bodySupported by a number of bearings in a particular flowing form in whichthe bearings are [52] placed in such relative positions as to cause thebody 1 Int Cl l k 4 to assume a desired shape, and while the body andthe [58] Field of Search "83/1, 16, 13, 171 542 556 bearings are beingpositioned relative to each other,

83/565, 699, 926 B; 76/101 R; 33/174 G they are rotated about theirrelative geometrical axes.

Also an apparatus for carrying out this process is disclosed.

11 Claims, 9 Drawing Figures PATENTEDFEB 6|975 3.714.855 SHEET 10F 2 4F|G.1 I FIG. 3

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INVENTOR PIETER K. NOORDENBOS 32%; 9M, mww

ATTORNEYS PATENTEDFEB 6l975 3,714,855 SHEET 20F 2 FIG.5

E i f: "l j F G. 9 INVENTOR PIETER K. NOORDENBOS 17m, 69 %& M

ATTORNEYS PROCESS AND APPARATUS FOR SETTING A FLEXIBLE ELONGATE BODY INA PARTICULAR FORM This invention relates to a precess and apparatus forsetting a flexible elongate body, especially a wireshaped or rod-shapedbody, in a particular form in which the body is supported by a number ofbearings that are placed in such relative positions as to permit thebody to assume a desired flowing form without any sudden changes in itsshape. The term setting as used herein refers to giving the body adesired form which is subsequently maintained for a given period oftime, or giving the body a form which continuously changes.

In a known precess a wire-shaped c utter cuts through a block of formingmaterial in order that a shaped object may be formed therefrom. In thisprecess the cutter is supported in bearings whose relative positionsdefine the shape of the cutter and consequently the contours of theobject formed. Although the cutter is made of a flexible material, it isnot always found to be shaped into the desired flowing form. Moreover,the cutter is subject to sudden changes in shape which are apparentlydue to the effects of friction at the points where the cutter issupported in the bearings. These changes manifest themselvesparticularly when the cutter is highly curved. This often occurs-infollowing contours which have a low radius of curvature. As a result,the surface of the workpiece shows irregularities which call for anadditional forming treatment.

Advantageously, the process according to the invention overcomes thesedrawbacks; Thus this invention contemplates a process for setting aflexible elongate body in a particular flowing form, which comprisessupporting the flexible body by a number of bearings, placing thebearing in such relative positions that the body is caused to assume adesired shape, and while the body and bearing are being positionedrelative to each other, rotating the bearings and the body,respectively, about their relative geometric axes.

This process leads to remarkably favorable results. The wire-shaped orrod-shaped body exactly and rapidly follows rapid and drastic changes inshape while constantly maintaining a flowing form. The relative rotationof the wire-or rod-shaped body and its bearings may be effected bycausing only the bearings to rotate or by causing the bearings and thebody to rotate at different speeds.

The simplest process in accordance with thisinvention, however, consistsin that only the wireor rodshaped body is caused to rotate.

The process can be effected in various ways. In one embodiment of theprocess of this invention the wireor rod-shaped body serves as a copyingmember which is followed by a tracing member. In that case a machinepart or element may be caused to describe a path which is defined by theshape of the wireor rod-shaped body.

In another embodiment the wireor rod-shaped body serves as a cuttingtool by which a shaped object is cut from a block of forming materials,e.g., a thermoplastic mass.

This invention also is directed to an apparatus for setting a flexiblewireor rod-shaped body, supported by a number of bearing, into a flowingform in accordance with a particularly desired curve, the ap paratuscomprising means for positioning the bearings in such relative positionsas to permit the body to be formed along the desired curve.

The apparatus of this invention is further characterized in that body iscoupled to a drive for the rotation of the body about its geometricalaxis and the bearings are so supported by the positioning means that thebearings are each pivotal about at least one axis transverse to thebody.

A very effective embodiment of the apparatus of this invention ischaracterized in that the drive is formed by a drive motor. The motormay be an electric motor or a pneumatically or hydraulically drivenmotor.

This invention is also concerned with an embodiment of the apparatus forthe production of shaped objects from a block of forming material, e.g.,a thermoplastic mass. This apparatus comprises a wireor rod-shaped bodythat serves as a cutting tool, a positioning means in the form ofplurality of movable followers which carry at one end the bearingssupporting the body, and means for effecting relative movement betweenthe block of forming material and the cutting tool.

A preferred embodiment of the apparatus is characterized in that thesupport bearings are formed by bearing sleeves which embrace the wireorrod-shaped body only partly. This embodiment is of importance both forthe case where the wireor rod-shaped body serves as a copying member andfor the case where it functions as a cutting tool for working a block offorming material. In the first case the tracing can be effectednon-interruptedly since the tracing member need not run in contact withthe bearings. In the second case the bearing sleeves are each providedwith an opening on the side of the workpiece which prevents the bearingsfrom cutting grooves into the workpiece.

In order to facilitate the cutting operation it is recommended that thebearings are supported by a cutter-functioning end of the followers.This is of particular importance if in a single pass much material is tobe cut and the ends of the followers penetrate fairly deeply into theworkpiece.

It is then preferred that the follower end functioning as cutter isformed by a plurality of cutting wires.

A very suitable embodiment of this apparatus is characterized in thatthe end functioning as cutter is formed by three or more cutting wireswhich form the ribs of a threeor more sided pyramid whose vertex isconnected to a bearing sleeve and whosebase is connected to a follower.

For the cutting of thermoplastic material, the apparatus of thisinvention is preferably provided with means for heating the cutter endsof the followers as well as the wire-shaped body.

The invention will be further described with reference to its specificembodiments and to the ac- FIG. 5 shows a support of the cutting wirebearing,

which support serves as a cutter;

FIG. 6 shows another embodiment of the support shown in FIG. 5;

FIGS. 7 and 8 illustrate a special embodiment of the cutting wirebearing in side elevation and in cross-section, respectively; and I IFIG. 9 shows an enlarged detail of the apparatus of the invention. Y

In the apparatus shown in FIGS. 1 and 2 a threedimensional model 2 hasbeen made with the aid of steel profiles or wire-like bodies 1. Theprofiles 1 may be bent along the waterlines of a sketch plan for a shipmodel. The profiles are attached to a holder 4 by means of supports 3.Each of the profiles 1 is traced by a follower S which is slidablysupported in a follower carriage 6. The follower carriage is moved pastthe holder 4 and the three-dimensional model 2. During this movement theleft ends of the followers 5 are in contact with the profiles 1, whileexercising a slight pressure thereon.

The right ends of the followers 5 are so coupled to a flexible andresilient, electrically heated cutting wire 7 that the wire is freelymovable in its axial direction.

Mounted on a workpiece table 8 is a block of forming material, forinstance of foamed polystyrene 9, which during the movement of thefollower carriage 6 is severed by the cutting wire 7. In this way, theworkpiece 9 will be given a form which corresponds to that of thethree-dimensional model 2.

As'already mentioned, the cutting wire 7 in the known apparatus does notalways assume the desired flowing form as a resultof friction at thesupporting points. y

In accordance with this invention the construction of this typeofapparatus has now been improved as indicated in FIG. 3. The support ofthe followers 5 by the carriage 6 (FIGS. 1 and.2) is represented by thebearings 10. Each of the followers have at their left end a pivotalcutting wi're bearing 11 which is shown in more detail in FIG.'4. Thecutting wire bearing consists of a sleeve 12 having a length whichequals abouttwice the diameter of the cutting wire 7. The bearing sleeve12 is supported by a fork 13, which, is positioned at the end of thefollower 5. At the bearing sleeve 12 there are provided two pins 14, 15which rest in the fork 13. As a 7 result, the bearing sleeve'l2 ispivotal about an axis perpendicular to the plane of the cutting wire 7.

Attached to the top follower in FIG. 3 is a small'ele'ctric motor 16,which is connected to the cutting wire 7.

The electric motor 16 can pivot about a shaft 17 perpendicular to theplane of the cutting wire 7. The motor is connected to a source of power(not shown) by means of flexible leads 18.

During operation, when the cutting wire is moving through the formingmaterial, itis rotated by the electric motor. As a result, the cuttingwire assumes, without now being subject to shocks, a flowing form, bothin the case of a high curvature of the wire and in the case of highfriction at the cutting wire bearings.

The wire cutter 7 need not beround, nor is it necessary for it to make arotation at constant angular velocity in a'single direction. It is alsocontemplated that rotation of the cutter to the left rapidly alternateswith rotation to the right. The rotation need not be effected by meansof a-drive motor. The cutter may also be rotated manually..

Nevertheless, the most favorable results are obtained with a wire cutterwhich has at least a substantially limeters thick, whichis attached tothe follower 5 but electrically insulated therefrom. The two ends of theV- shaped steel wire are connected to a current source (not shown) bymeans of flexible leads 88, 89. As a result, the wire 87 is electricallyheated. Both the shape and the heating of the end 87 of the followercontribute to realizing a smooth cutting through a thermoplastic formingmaterial.

FIG. 6 shows an embodiment in which the end of the follower includesfour cutting wires 90, 91, 92, and 93. They form the ribs of afour-sided pyramid whose vertex is connected to the cutting wire bearing11 and whose base is connected to the follower 5. As a result, a rigidconstruction of the follower end is obtained. The

1 four. cutting wires 90 up to and including 93'may con- FIGS. 7 and 8show an embodiment of a cutting wire bearing in detail which is somewhatdifferent from the one shown in FIG. 4. Like parts-are referred to bylike reference numerals. The cutting wire bearing consists of a sleeve12 which only embraces a portion of the circumference of the cuttingwire 7. As a result, part of the cutting wire facing the thermoplasticworkpiece projects from the sleeve 12. In this way the bearing sleeves12 are prevented from making grooves in the surface of the workpiece.

Just as in the embodiment shown in FIG. 4, the sleeve 12 is mountedpivotal in a fork 13. Welded to the FIG. 6.

FIG]. 9 shows in detail how the profiles 1- ofthe ap Y paratus' shown inFIGS. 1 and 2 are attached to the supports. Each support consists of atube 32 which has a fork-shaped end. Welded to this end are twobearingsleeves 33', 34 which pivotallysupport the pins 35, 36 of theprofile bearing 21. The round profile 1 having a round cross-section isslidable in the profile bearing21.

The profile bearing 21 does not embrace the profile 1 entirely, butleaves part of it free with regard to the tracing of the profile.

Against the free part of the profile rests a roller 38 which rotates ona shaft 39. The shaft 39 is attached to the follower 5, which is formedby a tube 40. p During the movement of the supports 3 the positioning ofthe profiles 1 serving ascopying member is facilitated by rotating theprofile and the cutting wire about their geometrical axes. Thepositioning of the profiles is facilitated even more by their beingsupported with the aid of pivotal bearings 21 which can pivot about axesperpendicular to the profiles.

It will be appreciated that the process and apparatus according to theinvention may be applied in general for the positioning of a wire-shapedor rod-shaped body along a two-dimensional or three-dimensional curve,which may or may not be continuously changing. The body may either serveas a copying member (for instance, in a machine tool for carrying out acutting operation, a grinding operation, a treatment by sparkerosion,and electrochemical operation) or be used as a forming tool.

The above-described processes and apparatus may serve, for instance, inthe design and production of models and molds for:

l. the flow measure (aeroand hydro-dynamics) in ships, aeroplanes, andturbo machines;

2. the manufacture of turbo machines;

3. the production of concrete articles (used in civil engineering);shell roofs, basins, and form blocks;

4. the manufacture of plastic objects reinforced with fiber material;

5. the production of molds, for instance for casting ships screws;

6. the production of objects from ferrocement (seacrete); these areobjects of concrete having a very high proportion of reinforcement; and

7. the manufacture of foamed plastic objects (furniture bodies and theirmolds, radar domes, radar antennae, sandwich fillings).

What is claimed is:

1. In a process for setting a flexible elongate body in a desired formwherein said body is supported by a number of bearings placed in suchrelative positions as to cause said body to assume the desired form,

the improvement which comprises rotating said body about its geometricalaxis while said bearings are being positioned relative to each other.

2. The process of claim 1 in which the elongate body serves as a copyingmember which is followed by a tracing member.

3. The process of claim 1 in which the elongate body is a flexible wirethat serves as a cutting tool for cutting a shaped object from a blockof forming material upon relative movement between the forming materialand the tool.

4. An apparatus for setting a flexible elongate body supported by anumber of bearings into a flowing form in accordance with a particularlydesired curve, said apparatus comprising means of positioning thebearings in such relative positions as to permit said body to be formedalong the desired curve, drive means coupled to the body for rotatingthe body about its geometrical axis and positioning means for supportingthe bearings so that the bearings are each pivotal about at least oneaxis transverse to the body.

5. The apparatus of claim 4, in which the drive means is formed by adrive motor.

6. The apparatus of claim 4, in which said apparatus further includesadditional means for producing a shaped object from a block of formingmaterial, said elongate body comprising a wire-shaped body that servesas a cutting tool, said positioning means comprising a plurality ofmovable followers each of which carry at one end one of the bearings forsupporting said body, and said additional means including filllide meansfor causing a relative movement between e block of forming material andthe cutting tool.

7. The apparatus of claim 6 in which the bearings are formed by bearingsleeves which only partly embrace the elongate body.

8. The apparatus of claim 6 in which each of said followers have acutter-functioning end and the bearings are each supported by thecutter-functioning end.

9. The apparatus of claim 8, in which the follower end functioning ascutter is formed by a plurality of cutting wires.

10. The apparatus of claim 9, in which the end functioning as cutter isformed at least three cutting wires which form the ribs of a pyramidhaving at least three sides, the vertex of the pyramid being connectedto a bearing sleeve and the base being connected to a follower.

II. The apparatus of claim 8, characterized in that means are providedfor heating the cutter ends of the followers.

1. In a process for setting a flexible elongate body in a desired form wherein said body is supported by a number of bearings placed in such relative positions as to cause said body to assume the desired form, the improvement which comprises rotating said body about its geometrical axis while said bearings are being positioned relative to each other.
 1. In a process for setting a flexible elongate body in a desired form wherein said body is supported by a number of bearings placed in such relative positions as to cause said body to assume the desired form, the improvement which comprises rotating said body about its geometrical axis while said bearings are being positioned relative to each other.
 2. The process of claim 1 in which the elongate body serves as a copying member which is followed by a tracing member.
 3. The process oF claim 1 in which the elongate body is a flexible wire that serves as a cutting tool for cutting a shaped object from a block of forming material upon relative movement between the forming material and the tool.
 4. An apparatus for setting a flexible elongate body supported by a number of bearings into a flowing form in accordance with a particularly desired curve, said apparatus comprising means of positioning the bearings in such relative positions as to permit said body to be formed along the desired curve, drive means coupled to the body for rotating the body about its geometrical axis and positioning means for supporting the bearings so that the bearings are each pivotal about at least one axis transverse to the body.
 5. The apparatus of claim 4, in which the drive means is formed by a drive motor.
 6. The apparatus of claim 4, in which said apparatus further includes additional means for producing a shaped object from a block of forming material, said elongate body comprising a wire-shaped body that serves as a cutting tool, said positioning means comprising a plurality of movable followers each of which carry at one end one of the bearings for supporting said body, and said additional means including guide means for causing a relative movement between the block of forming material and the cutting tool.
 7. The apparatus of claim 6 in which the bearings are formed by bearing sleeves which only partly embrace the elongate body.
 8. The apparatus of claim 6 in which each of said followers have a cutter-functioning end and the bearings are each supported by the cutter-functioning end.
 9. The apparatus of claim 8, in which the follower end functioning as cutter is formed by a plurality of cutting wires.
 10. The apparatus of claim 9, in which the end functioning as cutter is formed at least three cutting wires which form the ribs of a pyramid having at least three sides, the vertex of the pyramid being connected to a bearing sleeve and the base being connected to a follower. 